Fw: [ATM] Size does matter

["Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>]

Forgot the bottom line:

Of course it is better to balance. If you do as calculated below, it will
consequently take a force of 2 pounds to move the scope when pointed to
zenit. Also, elevating when in horizontal state will now be like lifting a
sixpack.

/a

----- Original Message ----- 
From: "Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>
To: <atm@atmlist.net>
Sent: Sunday, 19 December, 2004 17:46
Subject: Re: [ATM] Size does matter


> Jeff,
>
> You need some more input to calculate this. Assuming that the two pounds
is
> at the eyepiece, it matters where you are looking. Max arm when at
horizon,
> i.e. 24" x 2 lbs.
>
> Then you would need the total weight of the scope (OTA), and the angle
> (w.r.t. vertical) of the pads in the RA bearing to calculate the normal
> force (or weight, which in this case can also be used, provided you do
this
> consistently). Mutiply weight, 0.04, 1/cos(angle) and the trunnion
diameter
> to get the force (weight?) couple. This should be larger than the worst
case
> calculated above, i.e. 48 " lbs in your example.
>
> Hope this helps?
>
> /Arjan
>

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